Pinaud Julien, Trinh Thi Kim Hoang, Sauvanier David, Placet Emeline, Songsee Sriprapai, Lacroix-Desmazes Patrick, Becht Jean-Michel, Tarablsi Bassam, Lalevée Jacques, Pichavant Loïc, Héroguez Valérie, Chemtob Abraham
ICGM Univ Montpellier, CNRS, ENSCM, Montpellier, France.
Institute of Mulhouse Material Science, UMR-CNRS 7361, University of Haute-Alsace, 15 rue Jean Starcky, 68057, Mulhouse Cedex, France.
Chemistry. 2018 Jan 9;24(2):337-341. doi: 10.1002/chem.201705145. Epub 2017 Dec 12.
1,3-Bis(mesityl)imidazolium tetraphenylborate (IMesH BPh ) can be synthesized in one step by anion metathesis between the corresponding imidazolium chloride and sodium tetraphenylborate. In the presence of 2-isopropylthioxanthone (sensitizer), an IMes N-heterocyclic carbene (NHC) ligand can be photogenerated under irradiation at 365 nm through coupled electron/proton transfer reactions. By combining this tandem NHC photogenerator system with metathesis inactive [RuCl (p-cymene)] precatalyst, the highly active RuCl (p-cymene)(IMes) complex can be formed in situ, enabling a complete ring-opening metathesis polymerization (ROMP) of norbornene in the matter of minutes at room temperature. To the best of our knowledge, this is the first example of a photogenerated NHC. Its exploitation in photoROMP has resulted in a simplified process compared to current photocatalysts, because only stable commercial or easily synthesized reagents are required.
1,3-双（均三甲苯基）咪唑四苯基硼酸盐（IMesH BPh ）可通过相应的咪唑氯化物与四苯基硼酸钠之间的阴离子复分解反应一步合成。在2-异丙基噻吨酮（敏化剂）存在下，IMes N-杂环卡宾（NHC）配体可在365 nm光照下通过耦合电子/质子转移反应光生。通过将这种串联NHC光生体系与复分解惰性的[RuCl (对异丙基苯)]预催化剂相结合，高活性的RuCl (对异丙基苯)(IMes)配合物可原位形成，从而在室温下几分钟内实现降冰片烯的完全开环易位聚合（ROMP）。据我们所知，这是光生NHC的首个实例。与目前的光催化剂相比，其在光ROMP中的应用简化了过程，因为仅需要稳定的商业试剂或易于合成的试剂。
